Arc furnace

ABSTRACT

An arc furnace installation has furnace electrodes supported by electrode arms, the electrodes being vertically movably passed through a raisable and lowerable furnace cover on a laterally movable furnace vessel and their arms being vertically slidably applied to vertical pillars extending upwardly and the pillars having lower ends supported by supporting means positioned above and laterally free from the furnace vessel and its cover, leaving the space laterally aound the furnace vessel and its cover free from bulky equipment. This space is enclosed by side walls and movable screens providing insulation against furnace operating noise but by moving the screens permitting lateral movement of the furnace.

United States Patent 1 1 Marchner Apr. 23, 1974 ARC FURNACE Inventor: Jan Marchner, Vasteras, Sweden Allmanna Svenska Elektriska Aktiebolaget, Vasteras, Sweden Nov. 22, 1972 Assignee:

Filed:

Appl. No.:

Foreign Application Priority'Data Dec. 1, 1971 Sweden 15361/71 References Cited UNITED STATES PATENTS 4/1964 Lindblom et al. 1379 5/1939 Moore 13/1 Primary ExaminerRoy N. Envall, Jr. Attorney, Agent, or Firm-Kenyon & Kenyon Reilly Carr & Chapin 5 7] ABSTRACT An arc furnace installation has furnace electrodes supported by electrode arms, the electrodes being vertically movably passed through a raisable and lowerable furnace cover on a laterally movable furnace vessel and their arms being vertically slidably applied to vertical pillars extending upwardly and the pillars having lower ends supported by supporting means positioned above and laterally free from the furnace vessel and its cover, leaving the space laterally aound the furnace vessel and its cover free from bulky equipment. This space is enclosed by side walls and movable screens providing insulation against furnace operating noise but by moving the screens permitting lateral movement of the furnace. around 5 Claims, 3 Drawing Figures ARC FURNACE The present inventon relates to an arc furnace with a roof or upper supporting construction arranged above the furnace.

The electrode arms supporting the electrodes are often elements which are exposed to inductive heating and which are often bulky. Another inconvenience is the noise which often surrounds furnaces.

The invention is aimed at a solution to the problem, among other things, of reducing the bulk of the electrode arms and therefore their inductive heating, and reducing the radiation of the furnace operating noise, and it is characterized in that the electrode arms required to mount the electrodes are fixed to pillars which are attached to and drawn through said roof or upper supporting construction, and in that sound insulating screens are arranged at the sides of the furnace. These screens can suitably be lowered around the furnace vessel, and in this way sound insulation is obtained and simultaneously protection is provided against fumes forcing their way out of the furnace. In a preferred case, fume suction devices can be arranged around the lowered screens in the closed space (formed by the screens with other walls).

The invention is schematically exemplified in the accompanying drawings by the three figures, of which FIG. 1 shows a furnace with electrodes seen from the side, generally in vertical section indicated by the line 11 in FIG. 2, and FIG. 2 the same furnace seen from above, in cross section taken on the line 2-2 in FIG. 1. FIG. 3 is a detailed view of the furnace space in cross section as indicated by the line 33 in FIG. 1.

FIGS. 1 and 2 show furnace electrodes 11-13 positioned at the corners of a triangle, suitably an equilateral triangle, and supported by electrode arms 15, 16, 17. The electrodes are drawn or vertically movably passed through a raisable or lowerable furnace arch or cover 14. The electrode arms are vertically slidably applied to pillars 18, 19, extending upwardly and having lower ends which are attached to the roof R above the furnace F or to an upper supporting construction arranged above the furnace. In this way, considerable space is savedat the sides of the furnace vessel 21, and the furnace can be moved laterially (after raising the electrodes) on its carriage 21a without the obstacles present in previous constructions. The electrode arms must be rigid because the flexible suspension of the electrodes, known in the Tysland-Hole furnace, cannot be used here because of the electrodynamic forces during the scrap melting, and a stable electrode control is necessary for lifting the electrodes clear from the roof, which has been achieved through the invention. For charging the scrap the furnace cover 14 must be lifted I and the furnace vessel 21 laterally moved, on its carriage 21 a, until free from under the roof R. For teeming through its spout 21b, only the electrodes must be removed, the furnace then tilting on its rocker beams 21c and rolling laterally.

The furnace is surrounded by the roof R, side walls SW and vertically adjustable screens 22, 23 applied in the vertically longitudinal direction, said screens being able to be lowered at or outside the furnace vessel and to define laterally a space around the furnace, which becomes heat and sound insulated. Fumes are also prevented from issuing out into the surrounding atmosphere.

Also furnace transformers 24 are arranged closed to the furnace and above the transformer power cables 25 which connect to electrode clamps (not shown) connecting with the electrodes, and these cables can easily be drawn through a partition wall of a transformer room TR above the roof R.

Conductors to the electrodes are arranged in a manner known per se from triangularly situated points in towards the electrodes, where they are connected and where the A connecton is arranged for three-phase alternating current connection. The Tysland-Hole conductor arrangement is suitable although the flexible electrode mounting arrangement cannot be used with this invention. The arms 15 to 17 must be rigid, being clearly shown by the drawings as cantilever arms sliding on the pillars 18 to 20 at one end and supporting an electrode weight by its other end, in each instance.

According to FIG. 3, fume suction devices are arranged both from the furnace vessel 21, as shown at 26, and from the space around the furnace vessel, defined laterally by the screens 22, 23 and the side walls SW. The fume suction device from the space around the furnace is shown at 27, and in this way a good working environment can be achieved for the furnace personnel, both with regard to air, sound and also layout (among other things through the electrode positioning). The space can be defined upwards by the roof and laterally, in addition to the let-down screens 22 and 23 by the side walls SW.

Lifting cables 22a and 23a for the screens22 and 23 are indicated by broken lines in FIG. 1, and removable tubes T are shown for making additions to the furnace vessel 21 through its cover 14.

Due to the pillars 18 to 20 and the electrode arms 15 to 17 being completely above the furnace vessel 21, as are the electrode cables, there is nothing to interfere with the walls SW and the screens 22 and 23 being positioned close to the furnace in the manner shown by the drawings.

The invention can be varied in many ways within the scope of the following claims.

I claim:

1. An arc furnace installation comprising a laterally movable furnace vessel having a raisable and lowerable furnace cover, arc electrodes vertically movably passed through said cover, electrode arms supporting said electrodes, pillars to which said arms are applied and are supported thereby for vertical movement, and means for supporting the lower ends of said pillars above and free from said laterally movable furnace vessel and furnace cover so that when said electrodes are drawn upwardly from said furnace cover said furnace can be moved laterally.

2. The installation of claim 1 in which movable vertical screens are positioned adjacent to said furnace vessel and its cover in the direction of the vessels lateral movability, and side walls are positioned adjacent to the sides of said furnace vessel and its cover, said screen and side walls laterally enclosing said furnace vessel and its cover and providing furnace operating noise insulation.

3. The installation of claim 2 in which said pillar supporting means comprises a roof over said furnace cover and which with said screens and side walls defines a substantially enclosed space around said furnace vessel and cover.

4. The installation of claim 3 in which said furnace vessel has means for sucking fumes therefrom.

5. The installation of claim 3 having means for sucking furnace fumes from said space and removing the fumes therefrom. 

1. An arc furnace installation comprising a laterally movable furnace vessel having a raisable and lowerable furnace cover, arc electrodes vertically movably passed through said cover, electrode arms supporting said electrodes, pillars to which said arms are applied and are supported thereby for vertical movement, and means for supporting the lower ends of said pillars above and free from said laterally movable furnace vessel and furnace cover so that when said electrodes are drawn upwardly from said furnace cover said furnace can be moved laterally.
 2. The installation of claim 1 in which movable vertical screens are positioned adjacent to said furnace vessel and its cover in the direction of the vessel''s lateral movability, and side walls are positioned adjacent to the sides of said furnace vessel and its cover, said screen and side walls laterally enclosing said furnace vessel and its cover and providing furnace operating noise insulation.
 3. The installation of claim 2 in which said pillar supporting means comprises a roof over said furnace cover and which with said screens and side walls defines a substantially enclosed space around said furnace vessel and cover.
 4. The installation of claim 3 in which said furnace vessel has means for sucking fumes therefrom.
 5. The installation of claim 3 having means for sucking furnace fumes from said space and removing the fumes therefrom. 